The Efficacy of Amlodipine and Diltiazem in Cyclosporine Dose Adjustment with Respect to Trough and 2-hour Concentrations in Kidney Transplant Patients

Background & Aims: Hypertension, hyperuricaemia and nephrotoxicity are some common side-effects of Cyclosporine A (CsA) treatment in renal transplant recipients. Previous studies suggest that Calcium Channel Blockers (CCB) can increase serum level of CsA and may improve graft function in patients receiving CsA. The aim of this study was to evaluate the effects of Diltiazem and Amlodipine on cyclosporine dose adjustment with respect to trough and 2-hour concentrations in renal transplant recipients treated with CsA. Methods: This observer-blind randomized clinical trial was performed on 120 renal transplant recipients treated with CsA. Patients received either Amlodipine (5-10mg/day) or Diltiazem (90-180mg/day) for 3 months and were compared with control group receiving no CCB. Data were analyzed using ANOVA, Post Hoc and Correlation tests. Results: Diltiazem significantly decreased CsA dosage (20%) from 162.03± 40.6 mg/dl to 128.5± 25.5 mg/dl (P=0.000) and Amlodipine, too, decreased it to 140.5± 22.3 mg/dl (13%) which was significant (P=0.008). Trough concentration in patients who had received Amlodipine were significantly higher than control group (P=0.019). Diltiazem significantly decreased Cholesterol Level (P=0.027) but other parameters were not significantly different between Amlodipine / Diltiazem and control groups. Discussion: Diltiazem and Amlodipine were well tolerated in co-administration with CsA with no adverse effect on graft function and did not affect blood pressure or heart rate. Our findings support that these two CCBs can be used in clinical settings to reduce the administered dose of cyclosporine.